KR100510653B1 - Apparatus for correcting image distortion in digital TV - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for correcting image distortion of a digital TV, and more particularly, to correct an optical or physical image distortion that may occur in a projection TV, a projection display device widely used in a digital TV, a projector, or a direct-view TV using a CPT. By combining warping, format conversion, and OSD functions, the required hardware and memory usage and memory bandwidth can be minimized. In particular, it enables format conversion function and multi-screen configuration necessary for digital TV while minimizing required hardware and memory usage, and can correct optical distortion while providing menu screen such as OSD.

Description

Apparatus for correcting image distortion in digital TV}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for correcting distortion of an image that may occur in a projection TV, which is widely used as a display device of a digital TV, and more particularly, to a digital TV for correcting distortion of an image generated in a display unit using digital image processing. An image distortion correction apparatus.

With the introduction of digital TVs and the development of various display devices, it is possible to watch high resolution images that were difficult to imagine in conventional analog TVs through large display devices. In particular, projection-type display devices such as projection TVs and projectors are widely used as display devices of high-definition digital TVs (eg, HDTVs) because of their advantages of easy configuration in large screens.

The projector has an advantage of constituting the largest screen compared to other display devices. Therefore, in addition to the purpose of being connected to a display device of a PC and used for work such as seminar presentation, its use is gradually expanding from a home to a display device of a digital TV.

In the case of the projector, keystone correction is required as an additional function not found in other display devices. That is, in the case of other display devices, the keystone correction does not need to be frequently performed because the image scanning unit and the screen are included in the display device. However, the keystone correction function is essential because the projector uses a screen separately. For example, when the projector is installed on the ceiling, the image is projected downward, which causes the light path in the lower part to be much longer than the light path for the upper part of the image. On the other hand, when the projector is installed on the desk or the floor, the case is reversed, and the light path of the upper part is longer than the lower part. Therefore, in order to display the rectangular shape on the screen, the display must be corrected in reverse trapezoid shape before projecting the image. And since the installation state of the projector can be changed at any time, the keystone should be adjusted arbitrarily.

In addition, the conventional projection TV does not require various keystone adjustments like the projector, but as the thickness of the projection TV is reduced, the optical path difference between the upper part and the lower part of the scanning unit and the screen becomes larger, and thus the keystone adjustment needs to be performed at the production stage. In addition, due to distortion caused by the light path difference between the center of the screen and the outside of the screen, a function such as correction of pincushion is necessary.

As the display becomes larger, the distortion of the image due to the difference in optical paths becomes larger, and in order to reduce such distortion, conventionally, a system for designing an optical part with high precision, using a large number of lens parts, or directly or mechanically moving the lens part is adjusted. Used.

For example, US Pat. No. 5,978,051 (Jeffrey A. Gohman and Michael G. West, Image projection system with variable display format; referred to as Ref. 1) adjusts the lens system mounted in multiple stages as needed. A method of minimizing optical distortion is disclosed. However, for this purpose, the reference 1 should be designed to move the lens system, which is an expensive device, thereby increasing the cost of the projector, and also causing optical errors as the keystone or pinktion is corrected many times. As the display quality decreases, it is necessary to frequently calibrate. In addition, due to mechanical vibration, there are many difficulties, such as the amount of optical correction gradually changes over time, so that the correction must be repeated periodically.

As a method of solving this problem, a digital image processing method for correcting an optically generated image distortion into a digital image is disclosed in US Pat. No. 5,204,944 (George Wolberg and Terrance E. Boult, Separable image warping methods and systems using spatial lookup tables). (Hereinafter referred to as Ref. 2). That is, Reference 2 provides a method of solving optical distortion by using a warping technique. However, in the case of Reference 2 described above, the hardware structure is so complex that there is a difficulty in applying it directly to the digital TV.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to simultaneously perform a format conversion function, which is essential for image signal processing of a digital TV, and a warping function of correcting optical distortion generated in the display unit by an image processing method. To provide an image distortion correction apparatus for a digital TV.

Another object of the present invention is an image distortion of a digital TV that includes an on-screen display (OSD) function in a digital TV having a format conversion function or a display function such as PIP or POP and corrects an image distortion generated in a display device. In providing a correction device.

The image distortion correction apparatus of the digital TV according to the present invention for achieving the above object, while minimizing the required memory and memory bandwidth, the format conversion function and optical distortion generated in the display unit essential for processing the image signal of the digital TV It is to simultaneously perform the warping function to correct the image processing method.

The apparatus for correcting image distortion of a digital TV according to an embodiment of the present invention, which is configured as hardware, includes a memory for storing image data during format conversion or distortion correction of an input image, and distortion correction for the input image. In this case, the horizontal format conversion of the input image is performed first and stored in the memory, and then the format conversion unit performs vertical format conversion as needed while reading the image stored in the memory, and distortion of the input image. When correction is to be performed, the image input through the format conversion unit is first corrected in the vertical direction to compensate for optical distortion and stored in the memory, and then the image stored in the memory is read in the horizontal direction. It includes an image distortion correction unit for performing correction corresponding to the optical distortion. Characterized in that the configuration.

The present invention further includes an OSD unit for synthesizing OSD data necessary for the format-converted image, and when distortion correction is to be performed on the input image, the OSD data is read from the memory in a vertical direction and synthesized with the image. It features.

The present invention is characterized in that the color coordinate conversion unit for converting the color coordinates of the input image into the form of color coordinates required by the display device is further provided between the OSD unit and the image distortion correction unit.

The format converter may include a vertical format converter that enlarges or reduces an input image in a vertical direction, a horizontal format converter that enlarges or reduces an input image in a horizontal direction, and before and after the vertical and horizontal format converters. It is characterized by consisting of a plurality of mux to control the input and output data path of the image according to the size of the input and output image and the image distortion correction.

If the horizontal and vertical resolutions of the output image are larger than the horizontal and vertical resolutions of the input image as the image distortion correction is performed, first, the format converter outputs the input image to the horizontal format converter to increase the horizontal resolution. And store the image in a memory, and then output the image read out from the memory to a vertical format converter to increase the resolution of the image in the vertical direction and output the image distortion correction.

When the image distortion correction is performed and the horizontal resolution and the vertical resolution of the output image are both smaller than the horizontal / vertical resolution of the input image, the format converter converts the vertical resolution and the horizontal resolution of the input image to the vertical format conversion. The first and second horizontal format converters first reduce and then store the data in the memory, and then read the data in the vertical direction from the memory and output the image distortion correction.

When the image distortion correction is performed and the horizontal resolution of the output image increases and the vertical resolution decreases, the format converter reduces the vertical resolution of the input image by the vertical format converter, and then reduces the horizontal resolution by the horizontal format converter. It is increased and stored in the memory, and then read in the vertical direction from the memory and output for image distortion correction.

When the image distortion correction is performed and the horizontal resolution of the output image is reduced and the vertical resolution is increased, the format converter reduces the horizontal resolution of the input image by the horizontal format converter and stores the horizontal resolution in the memory. The image read out from the memory is output to the vertical format converter to increase the resolution of the image in the vertical direction and to output the image distortion correction.

According to the present invention, when two or more images are simultaneously displayed on a screen, a plurality of format converters and a mux for synthesizing the outputs of the plurality of format converters are configured to perform horizontal and vertical format conversion for each of the images. When distortion correction is to be performed on the input image, the MUX is characterized in that a plurality of format converters read and format images converted in a vertical direction and synthesize the same.

According to the present invention, when multiple images are input to simultaneously display two or more images on a screen, a color coordinate conversion unit for matching the color coordinates of the input images to one color coordinate is provided in front of the plurality of format conversion units, respectively. It is done.

According to another aspect of the present invention, an apparatus for correcting image distortion of a digital TV may include a memory for storing image data during format conversion or distortion correction of an input image, and distortion correction for the main screen image. A main screen format conversion unit which performs horizontal format conversion of the input main screen image first and stores it in the memory, and then reads the main screen image stored in the memory and performs vertical format conversion as necessary; When distortion correction is to be performed on the sub-screen image, horizontal format conversion of the input sub-screen image is first performed and stored in the memory, and thereafter, the sub-screen image is read out and the vertical format is read as necessary. A sub-picture format converting unit for converting and outputting the main / sub-screen format converting unit, When distortion correction is to be performed on an input image, a mux for reading and synthesizing a format-converted image in the vertical direction by the main / sub picture format converter and OSD data required when distortion correction is to be performed on the input image. An OSD unit configured to read a vertically from the memory into a format-converted image output through the MUX, a color coordinate converting unit converting color coordinates of the image input through the OSD unit into a color coordinate form required by a display device; When distortion correction is to be performed on the input image, the image input through the color coordinate converter is first corrected for optical distortion in the vertical direction and stored in the memory, and then the image is stored in the memory. While reading the correction in the horizontal direction corresponding to the optical distortion Including image distortion correction unit which is characterized in that configuration.

The present invention is characterized in that the color coordinate conversion unit for matching the color coordinates of the input main / sub-screen image into one color coordinate is further provided in front of the main / sub-screen format conversion unit.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings illustrating the configuration and operation of the embodiment of the present invention, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, By the technical spirit of the present invention described above and its core configuration and operation is not limited.

1 is a block diagram illustrating an apparatus for correcting image distortion for a digital TV according to an embodiment of the present invention. The format conversion unit 200 converts the size of an input image according to a display resolution, and the format conversion unit 200 performs format conversion. OSD coordinates for displaying menu information, caption information, data broadcasting information, etc. in the image; color coordinate conversion for converting to RGB image format when the color coordinates of the image input through the OSD unit 300 are YCbCr type. The unit 400 and an image distortion correcting unit 500 for warping the image in consideration of an optically generated distortion of the color coordinate converted image are configured.

1, the memory 100 is provided so that the image converted in accordance with the size of the input and output image or the image distortion correction is output directly to the OSD unit 300 or from the memory 100 to the OSD unit 300, The image distortion corrected data in the image distortion correction unit 500 is stored as it is or stored in the memory 100 and then output for display.

In the present invention configured as described above, the format conversion unit 200 converts the resolution of the input image into the resolution of the output image. In addition, the sampling format of the input image may be various, such as 4: 2: 0, 4: 1: 1, 4: 2: 2, 4: 4: 4, etc. The format converter 200 may display or display the image. It also converts to a sampling format for easy distortion correction.

In this case, the format converter 200 may operate differently when the image distortion correction is performed and when the image distortion correction is not performed. That is, the format conversion unit 200 moves in conjunction with an image distortion correction operation, and when image distortion correction is to be performed, horizontal format conversion of the image is performed first, and then the image is first stored in the memory 100. do. Thereafter, the image stored in the memory 100 is read and vertical format conversion is performed if necessary.

2 is a detailed block diagram of the format conversion unit, wherein a vertical format conversion unit (VFC) 201 including a mux, a horizontal format conversion unit (HFC) 202 including a mux, an input image, and the vertical format conversion unit 201 are shown. MUX 203 for selecting and outputting any one of the outputs of the MIX 203 and the output of the horizontal format converter 202 and the output of the MUX 203 in the memory 100 through a memory interface (not shown). The write interface unit 204, the read interface unit 205 for reading data stored in the memory 100 through the memory interface, the output of the vertical format converter 201, and the horizontal format converter 202. And a mux 206 for selectively outputting any one of an output and an output of the read interface unit 205.

The format converting unit 200 is converted into several modes according to the size of the input image, the size of the output image, and the case where the image distortion is corrected or not. In this case, the mode conversion of the format converter 200 is performed by controlling the data path of the input image through a plurality of muxes located in the format converter. For convenience of description, FIGS. 3 and 4 omit the illustration and operation of the read / write control unit and the mux.

First, when the image distortion correction is not performed, operation of the memory used for format conversion is minimized as shown in FIGS. 3A to 3D. That is, as in the four modes of FIGS. 3A to 3D, the operation is performed in four forms according to the ratio of the horizontal / vertical resolution of the input image to the horizontal / vertical resolution of the output image, and is filed by the present applicant (application number: 2000-1420). In this case, when the input image is enlarged or output as it is, a display clock is required for format conversion, and when the input image is reduced, an input clock is required for format conversion. This applies equally to vertical and horizontal format conversion.

First, when the horizontal resolution and the vertical resolution of the output image are equal to or larger than the horizontal / vertical resolution of the input image, the operation is performed in mode A of FIG. 3A. That is, the input image is first stored in the memory 100, and then the vertical format converter 201 and the horizontal format converter 202 are sequentially read in the vertical direction and the horizontal direction while reading the image stored in the memory 100. The display is increased while increasing the resolution of the image.

In addition, when the horizontal resolution and the vertical resolution of the output image are both smaller than the horizontal / vertical resolution of the input image, the operation is performed in the mode B of FIG. 3B. That is, the input image is passed through the horizontal format converter 202 and the vertical format converter 201 in order to reduce the resolution in the horizontal direction and the vertical direction first, and then stored in the memory 100, and then in the horizontal and vertical directions. The reduced image is directly read from the memory 100 and displayed.

When the resolution of the image increases in the horizontal direction and the resolution of the image decreases in the vertical direction, the mode C of FIG. 3C is operated. That is, the input image is first passed through the vertical format converter 201 to reduce the resolution in the vertical direction, and then stored in the memory 100. Thereafter, the image read from the memory 100 is input to the horizontal format converter 202 to display the image while increasing the resolution of the image in the horizontal direction.

In contrast to FIG. 3C, when the resolution of the image decreases in the horizontal direction and the resolution of the image increases in the vertical direction, the mode D of FIG. 3D is operated. That is, the input image is first passed through the horizontal format converter 202 to reduce the horizontal resolution, and then stored in the memory 100. Subsequently, the image read from the memory 100 is input to the vertical format converter 201 to display the image while increasing the resolution of the image in the vertical direction.

As such, when the image distortion correction is not performed, format conversion may be performed while minimizing the amount of memory required by processing the format conversion according to the resolutions of the input image and the display image having various sizes. .

On the other hand, when performing image distortion correction, the format converter 200 should operate slightly differently for smooth linkage with the image distortion correction unit 500. That is, regardless of the case where the horizontal resolution of the input image is increased or decreased as shown in FIGS. 4A and 4B, the input image must be processed first in the horizontal direction and then stored in the memory. The more detailed explanation is as follows.

For example, when the horizontal resolution and the vertical resolution of the output image are larger than the horizontal / vertical resolution of the input image while performing image distortion correction, the mode E is operated as shown in FIG. 4A. That is, the input image is first passed through the horizontal format converter 202 to increase the horizontal resolution and then stored in the memory 100. Thereafter, the image read from the memory 100 is input to the vertical format converter 201 to increase the resolution of the image in the vertical direction and output the image distortion correction. For this operation, the hardware of the horizontal processing portion of the format converter 200 increases, and it uses more memory than when the image distortion correction is not performed, but it is optimal when the image distortion correction is considered. You can configure the hardware. Then, the image distortion correction unit 500 performs image distortion correction on the image in which the format conversion is performed while reading the image in the vertical direction. At the same time, format conversion and image distortion correction can be processed, minimizing the use of overall hardware.

When the horizontal resolution and the vertical resolution of the output image are both smaller than the horizontal / vertical resolution of the input image, the operation is performed in the mode F of FIG. 4B, in which case the image distortion correction is not performed. It will work. That is, the vertical resolution and the horizontal resolution of the input image are first reduced in the vertical format converter 201 and the horizontal format converter 202 and then stored in the memory 100, and then immediately in the memory 100. Image is read and output for image distortion correction.

In addition, even when the horizontal resolution of the output image is increased and the vertical resolution is decreased, the operation is performed in the mode F of FIG. 4B. In this case, the vertical resolution of the input image is reduced by the vertical format converter 201, the horizontal format converter 202 increases the horizontal resolution, and then stores it in the memory 100, and then immediately vertically in the memory 100. Image is read in the direction and output for image distortion correction. In this case, since the horizontal resolution is increased and stored in the memory 100 in order to correct the image distortion, the format conversion itself has a disadvantage in that the hardware is increased and the use of the memory is increased. And the use of memory is minimized.

On the other hand, when the horizontal resolution of the output image becomes smaller and the vertical resolution becomes larger, the operation is performed in the mode E of FIG. 4A, in which case the operation is performed as if the image distortion correction is not performed. That is, the horizontal resolution of the input image is first reduced in the horizontal format converter 202 and then stored in the memory 100, and then, in the vertical format converter 201 for the image read from the memory 100. After increasing the resolution, it outputs to correct the image distortion.

That is, the image converted in the vertical / horizontal direction by the format converter 200 is output to the image distortion corrector 400 through the OSD unit 300 and the color coordinate converter 400.

The image distortion correction unit 500 corrects the input image by applying distortion to the image, and reversely corrects optical distortion generated in the display device of the digital TV in the image processing step so that the final display is normal. This is to make it possible.

5 shows optical distortion generally occurring.

That is, FIG. 5A illustrates a normal display form in which a shape of an input image is output as it is when there is no optical distortion as in the case of a flat panel display such as a PDP or LCD TV. FIG. 5B is the optical distortion that occurs most when an image is displayed using a projector, and is a symptom that occurs when the image of FIG. 5A is displayed by a projector installed on a ceiling. FIG. 5C illustrates an image in which a normal image is displayed when the projector is displayed in the lower right direction. FIG. 5D illustrates distortions of up, down, left and right pinktions that may occur in a projection TV or a direct view monitor. When the light source and the screen are very short, the path difference between the center and the outer part of the image is large.

As described above, various types of optical distortions exist, and the image distortion correction unit 500 may make the final display normally by applying the reverse correction to the image before the image is transferred to the optical unit in consideration of the optical distortion. have.

In this case, the image distortion correction unit 500 may be divided into the case of the image distortion correction and the case of not operating according to the display type. When the image distortion correction does not operate, the image distortion correction unit does not use the memory immediately. It only plays the role of printing.

On the contrary, when image distortion correction is performed, image processing is performed by separating the processing in the vertical direction and the processing in the horizontal direction as shown in FIG. 6. The distortion as shown in FIG. 5D represents a very complex distortion. In order to simply process the distortion, it is necessary to separately process the image processing method into a vertical image processing and a horizontal image processing. In addition, since the format conversion function should be performed before the image distortion correction operation, consideration thereof is also required.

That is, the image distortion correction unit 500 outputs the input image as it is, if not performing the image distortion correction, but if the image distortion correction is performed through the OSD unit 300 and the color coordinate conversion unit 400. The optical distortion of the input image is first corrected in the vertical direction and stored in the memory 100. Thereafter, the image stored in the memory 100 is read and displayed while performing correction corresponding to optical distortion in the horizontal direction.

FIG. 6 illustrates a more detailed block diagram of FIG. 5. The format converter 200 is divided into a horizontal format converter 200a and a vertical format converter 200b, and an image distortion corrector 500 is provided. ) Is divided into a vertical image distortion correction unit 500a and a horizontal image distortion correction unit 500b.

In consideration of such a comprehensive situation, when the image distortion correction is performed, the horizontal format conversion unit 200a performs format conversion in the horizontal direction on the input image and stores the converted image in the memory 100. After performing the format conversion in the vertical direction while reading the image from the memory 100, the image is provided to the image distortion correction unit 500 through the OSD unit 300 and the color coordinate conversion unit 400. In this case, since the format conversion unit 200 changes the size of the input image according to the display resolution, the image distortion correction unit 500 needs to consider the input format. There is no need to perform inverse correction of the optical distortion of the display.

That is, when the image is read in the vertical direction by the format converter 200, the image is corrected to the display screen size, and provided to the image distortion corrector 500, the image distortion corrector 500 is a vertical image distortion corrector 500a. Reverse correction of the optical distortion is performed first in the vertical direction, and is processed in synchronization with the format converter 200. In addition, the image of which the reverse correction in the vertical direction is finished is stored in the memory 100 again.

As described above, the image stored in the memory 100 is twice converted into display resolution for various types of input images, and the vertical image distortion corrector 500a corresponds to the optical distortion of the display unit in the vertical direction. It is reverse compensated. Therefore, when the image is read in the horizontal direction by the horizontal image distortion correction unit 500b and the reverse correction is performed in the horizontal direction once more, the final reverse corrected image is formed. The final inversely corrected image is directly applied to the display device or to the final display device through other image processing.

Meanwhile, in a digital TV, a data broadcasting image or a menu screen for a user is added to the input image using the OSD unit 300. In this case, the image distortion correction function for the OSD image as well as the image distortion correction for the input image are also added. It must be done at the same time.

To this end, the OSD unit 300 should be able to operate differently from the existing one.

That is, the existing OSD processing apparatus reads OSD data from a memory in accordance with a horizontal synchronization signal of an image signal and adds the OSD data to an input image for display. When the image distortion correction apparatus of the present invention does not perform image distortion correction, the OSD unit 300 is operated in the same manner as the conventional method.

However, when the image distortion correction unit 500 is operated to correct the distortion of the image, the image is input in the vertical direction instead of the horizontal direction when the image is input to the OSD unit 300. Therefore, in this case, the OSD unit 300 must perform an operation of adding OSD data to the format-converted image by reading OSD data from the memory in a vertical direction in synchronization with reading an image in a vertical direction.

At this time, when the format conversion unit 200 and the OSD unit 300 reads the image in the vertical direction, the format conversion unit 200 and the OSD unit 300 bundle the image into 4 or 8 line units in the vertical direction to perform format conversion or insert the OSD image. By doing so, the configuration of the memory map can be simplified, thereby minimizing the amount of memory required or the bandwidth of the memory.

In addition, in the case of digital TV, most input images are often input in the form of YCbCr. However, most display devices requiring image distortion correction need to receive an image signal in the form of an RGB signal.

To this end, it is necessary to perform image distortion correction on each signal after changing the input YCbCr color coordinate signal to an RGB color coordinate signal. Therefore, the color coordinate converting unit 400 is positioned behind the OSD unit 300 and before the image distortion correcting unit 500 to convert the color coordinates of the input image into color coordinates required by the display device.

In addition, in many cases, a projection TV has a separate light source for each of the signals of R, G, and B, or a different optical path for each of the signals of R, G, and B. This causes different optical distortion for each of the RGB signals. Therefore, in the image distortion corrector 500, a function of differently correcting optical distortion for each RGB signal is necessary.

Meanwhile, in the case of a digital TV, a function of simultaneously viewing two or more images such as picture in picture (PIP), picture out picture (POP), split screen, and the like is a basic function, and in this case, image distortion correction should be able to operate. FIG. 7 is a block diagram illustrating such a case, in which a format conversion unit may have two or more, and has a PIP mux unit 703 that forms a screen such as a PIP by synthesizing a plurality of screens. 7 illustrates an example in which two images, namely, a main screen and a sub-screen image, are simultaneously displayed. The main screen format converter 701 performs format conversion on an input image selected as a main screen image. And a sub-screen format converter 702 which performs format conversion on the input video selected as the sub-screen picture. Here, each format converter has the configuration as shown in FIG.

In this case, when the image distortion correction is not performed, the PIP mux unit 703 is performed in the same manner as in the conventional method, but when the image distortion correction is performed, as described above, the main / sub picture format converters 701 and 702 and the OSD are used. The unit 704 and the image distortion corrector 706 operate differently from the conventional method.

That is, the PIP mux unit 703 in the case where the image distortion correction is operated is operated to synthesize the image while reading the image in the vertical direction. In this case, the operation modes of the vertical format converters of the main / sub picture format converters 702 and 702 may be different from each other. That is, as described above, in processing in the vertical direction, the format converter may or may not increase the size of the vertical direction while reading an image. In this operation, the main screen format converter 701 and the sub-screen format converter 702 may operate differently. In addition, even if the two format converters increase the size of the image, the ratio may be different from each other.

In addition, when two or more images may have different color coordinates when an image is input through two or more input channels, the image input unit needs to consider the above-mentioned color coordinates to match one color coordinate. FIG. 8 is a block diagram of such a case, and each of the color coordinate conversion units (CSC) 801 and 802 is placed in front of the main screen format converter 701 and the sub-screen format converter 702 of FIG. Is added.

That is, when the RGB image is input to the main screen and the YCbCr image is input to the sub-screen, as shown in FIG. 8, the color coordinate converter 801 converts the color coordinates of the input image into the main screen format converter 701. The color coordinate conversion unit 802 converts the YCbCr type image into the RGB type image and outputs the color coordinate to the sub picture format conversion unit 702. Or, in the opposite process, the color coordinates are output unified.

As described above, according to the apparatus for correcting image distortion of a digital TV according to the present invention, the optical TV may be generated in a projection TV, a projection display device widely used in a digital TV, a projector, or a direct-view TV using a color picture tube (CPT). By combining the warping function, the format conversion function, and the OSD function to correct the video or physical image distortion, the required hardware and memory usage or the memory bandwidth can be minimized.

In addition, it enables format conversion function required for digital TV, multi-screen configuration such as PIP, POP, Split Screen, etc., while minimizing the required hardware and memory usage, and provides optical menus such as OSD to correct optical distortion. .

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1 is a block diagram of an image distortion correction apparatus of a digital TV according to the present invention;

FIG. 2 is a detailed block diagram of a format converter of FIG. 1.

3A to 3D are diagrams showing examples of respective operation modes of the format converter when image distortion correction is not performed in the present invention.

4A and 4B are diagrams showing examples of respective operation modes of the format converter when image distortion correction is performed in the present invention.

5A to 5D show general examples of normal display form and image distortion.

6 is a block diagram illustrating a more detailed block diagram of FIG. 1.

7 is a block diagram illustrating an image distortion correction apparatus for a two-screen mode according to the present invention.

FIG. 8 is a diagram illustrating an actual implementation of an image distortion correction apparatus further including a color coordinate converter in front of FIG. 7.

Explanation of symbols for main parts of the drawings

100: memory 200: format conversion unit

201,200b: vertical format converter 202,200a: horizontal format converter

300: OSD unit 400: color coordinate conversion unit

500: image distortion correction unit 500a: vertical image distortion correction unit

500b: horizontal image distortion correction unit

Claims (15)

A memory for storing image data during format conversion or distortion correction of an input image; When distortion correction is to be performed on an input image, horizontal format conversion of the input image is performed first and stored in the memory, and thereafter, vertical format conversion is performed as needed while reading the image stored in the memory. A format converter; A color coordinate converter for converting color coordinates of an image input through the format converter into an RGB form when distortion correction is to be performed on the input image; And When distortion correction is to be performed on the input image, the image input through the color coordinate converter is first corrected for optical distortion in the vertical direction and stored in the memory, and then the image is stored in the memory. And a video distortion correction unit for performing correction corresponding to optical distortion in a horizontal direction while reading the digital distortion of the digital TV. The method of claim 1, An OSD unit for synthesizing the OSD data necessary for the format-converted image is further provided between a format converting unit and a color coordinate converting unit. When distortion correction is to be performed on the input image, the OSD data is read out from the memory in a vertical direction. And a video distortion correction apparatus for synthesizing the video. delete The method of claim 1, wherein the format conversion unit A vertical format converter which enlarges or reduces an input image in a vertical direction; A horizontal format converter which enlarges or reduces an input image in a horizontal direction; Image distortion correction of a digital TV, characterized in that it is composed of a plurality of mux to control the input and output data path of the image according to the size of the input and output image and the front and rear of the vertical and horizontal format conversion unit and before and after the memory Device. The method of claim 4, wherein the format conversion unit When the horizontal and vertical resolutions of the output image are larger than the horizontal and vertical resolutions of the input image while the image distortion correction is performed, first output the input image to the horizontal format converter to increase the horizontal resolution and then the memory. And the image read out from the memory is then output to a vertical format converter to increase the resolution of the image in the vertical direction and to output the image distortion correction. The method of claim 4, wherein the format conversion unit When the horizontal and vertical resolutions of the output image are both smaller than the horizontal and vertical resolutions of the input image while the image distortion correction is performed, the vertical format converter and the horizontal format of the input image are converted to the horizontal and vertical resolutions. The apparatus for reducing image distortion of a digital TV, which is first reduced by a converter and then stored in the memory, and then read in the vertical direction from the memory and output for image distortion correction. The method of claim 4, wherein the format conversion unit If the horizontal resolution of the output image becomes larger and the vertical resolution becomes smaller as the image distortion correction is performed, reduce the vertical resolution of the input image in the vertical format converter, and then increase the horizontal resolution in the horizontal format converter. And storing the image in the memory, and then reading the image in a vertical direction from the memory to output the image distortion correction. The method of claim 4, wherein the format conversion unit If the horizontal resolution of the output image decreases and the vertical resolution increases while the image distortion correction is performed, the horizontal resolution of the input image is reduced by the horizontal format converter, and then stored in the memory, and then read from the memory. The image distortion correction apparatus of claim 1, wherein the image is output to the vertical format converter to increase the resolution of the image in the vertical direction and then output the image distortion correction. The image distortion correction unit of claim 1, In the image processing step, the optical distortion generated in the displayed image is corrected by adding distortion to the image, and when each RGB signal has a separate light source or the optical paths for the respective RGB signals are different. The image distortion correction device of the digital TV, characterized in that for correcting the optical distortion for each of the RGB signals. The method of claim 1, When displaying two or more images on the screen at the same time, a plurality of color coordinate conversion unit for matching the color coordinates of the input image to one color coordinate, and horizontal and vertical format conversion for the image output through the corresponding color coordinate conversion unit And a mux for synthesizing the outputs of the plurality of format converters, And distortion correction is performed on the input image, wherein the MUX reads the format-converted images in a vertical direction from a plurality of format converters and synthesizes them. A memory for storing image data during format conversion or distortion correction of an input image; When distortion correction is to be performed on the input main screen image, horizontal format conversion of the input main screen image is performed first and stored in the memory, and thereafter, the main screen image stored in the memory is read. A main picture format converter for performing vertical format conversion; When distortion correction is to be performed on the input subscreen image, horizontal format conversion of the input subscreen image is first performed and stored in the memory, and thereafter, the subscreen image stored in the memory is read out as necessary. A sub picture format conversion unit which performs vertical format conversion; A mux for synthesizing the output of the main / sub picture format conversion unit and reading and synthesizing the image converted by the main / sub picture format conversion unit in a vertical direction when distortion correction is to be performed on an input image; An OSD unit for reading out the necessary OSD data from the memory in a vertical direction and synthesizing it into a format-converted image output through the mux when distortion correction is to be performed on the input image; A color coordinate conversion unit for converting color coordinates of an image input through the OSD unit into a color coordinate form required by a display device; And When distortion correction is to be performed on the input image, the image input through the color coordinate converter is first corrected for optical distortion in the vertical direction and stored in the memory, and then the image is stored in the memory. And a video distortion correction unit for performing correction corresponding to optical distortion in a horizontal direction while reading the digital distortion of the digital TV. The method of claim 11, An apparatus for correcting image distortion of a digital TV, characterized in that a color coordinate converting unit for matching color coordinates of an input main / sub picture image to one color coordinate is further provided in front of the main / sub picture format converting unit. The method of claim 11, wherein each of the main / sub picture format conversion unit A vertical format converter which enlarges or reduces an input image in a vertical direction; A horizontal format converter which enlarges or reduces an input image in a horizontal direction; Image distortion correction of a digital TV, characterized in that it is composed of a plurality of mux to control the input and output data path of the image according to the size of the input and output image and the front and rear of the vertical and horizontal format conversion unit and before and after the memory Device. The method of claim 13, wherein each of the main / sub picture format conversion unit When the horizontal and vertical resolutions of the output image are larger than the horizontal and vertical resolutions of the input image while the image distortion correction is performed, or when the horizontal resolution of the output image is smaller and the vertical resolution is larger, the horizontal resolution of the input image is Orientation resolution is increased or decreased by the horizontal format converter and then stored in the memory, and then the image read out from the memory is output to the vertical format converter to increase the resolution of the image in the vertical direction and then output for image distortion correction. Image distortion correction device for a digital TV, characterized in that. The method of claim 13, wherein each of the main / sub picture format conversion unit When the horizontal and vertical resolutions of the output image are both smaller than the horizontal and vertical resolutions of the input image while the image distortion correction is performed, or when the horizontal resolution of the output image is larger and the vertical resolution is smaller, the input image The vertical resolution and the horizontal resolution of the vertical format converter and the horizontal format converter first converts and then stored in the memory, and then read in the vertical direction from the memory to output for image distortion correction Image distortion correction device for digital TV.